The Global Institute of Sustainable Forestry at the Yale School of Forestry & Environmental Studies

Program on Forest Physiology and Biotechnology
Program Chair: Dr. Graeme P. Berlyn

The Program on Forest Physiology and Biotechnology (PFPB) focuses primarily on the relationships of physiology, morphology, and genetics of forest plants to silviculture and sustainable forestry.

The main objectives of the biotechnology initiative are to analyze ecosystem impacts of biotechnology from biological, technical, and cultural perspectives; to evaluate strategies to minimize possible deleterious effects in these several dimensions; and to organize forums for discussion of the role of genetic techniques in forest health and forest tree improvement in ways that do not represent biological hazard to the future forests of the world. The use of genetically modified trees for restoration and removal of pollutants is also a consideration. When an organism is changed and introduced into an ecosystem or forest community there can be profound changes in both the above and below ground biota and this change can be positive or negative and therefore requires investigation.

Current research is focused around several projects, including the anatomical, physiological, and optical properties of leaves in relation to (a) light intensity and quality, (b) distribution in tree crowns, (c) nutrient status, and (d) ecology and silviculture. A goal of this work is to scale up from the leaf to the tree to the canopy and forest by interfacing reflectance and fluorescence and carbon uptake with hyperspectral data from high-resolution remote sensing. It is thought that these methods can provide reliable measurements of forest health.

Ultimately, these signals may also identify distribution of species within forest canopies along with measurements of foliar function such as photosynthesis, and cellular phenotypic plasticity (for instance, cuticle thickness, epidermal properties, and palisade versus spongy mesophyll). Such evaluations can be useful in evaluating sustainability under a variety of site conditions. In conjunction with these approaches, we are cooperating on studies of the anatomy and physiology of trees in many different areas of the world (India, Panama, Sri Lanka, Costa Rica) to determine optimal habitats for native species for sustainable forestry. Recent research in maize suggests that measurements of individual leaf chlorophyll can be used to calculate accurately the chlorophyll content of the whole canopy and that this value is a strong measure of the health and productivity of the stand. This approach has not as yet been applied to forests, but we are investigating this possibility.

Another long-term research project concerns the development and use of organic biostimulants to maintain optimum plant growth while reducing fertilizer requirements and increasing natural stress resistance with respect to water, disease, insects, and toxic substances. Graeme P. Berlyn was one of the originators of the biostimulant concept for amplifying plant growth and stress resistance. Current work involves adding beneficial microbes (or their byproducts) to the biostimulant such as mycorrhizas and organisms that inhibit pathogenesis and increase the natural resistance of the plant using chemical signaling to stimulate the production of protective compounds and protective tissues. Efforts are under way to improve the antioxidant systems (superoxide dismutase, ascorbic acid, and glutathione) in tree leaves in order to alleviate stress and increase productivity. This approach is also being worked on by genetically modifying plants to increase their internal production of antioxidants. The external application offers an advantage in that it has lower initial costs and can be easily terminated if problems develop. We are currently working with urban foresters and arboriculture on ways to monitor and improve the health of urban forests.

The program is located in the Greeley Laboratory, 370 Prospect Street. There are numerous opportunities for students to be involved with the research taking place through the program.